Pneumatic pulsator



Jan. 12, 195 4 5, J ERLlNG 2,665,703

PNEUMATIC PULSATOR Filed May 18, 1950 /nvenfor.

b5ven Johan Er/z'ng Patented Jan. 12, 1954 PNEUMATIC PULSATOR Sven Johan Erling, Nockeby, Sweden, assignor to Aktiebolaget Separator, Stockholm, Sweden, a corporation of Sweden Application May 18, 1950, Serial No. 162,798

This invention relates to an improved pneumatic pulsator of the type having a piston influenced by a diaphragm.

In the type of pulsator which comprises a valvepiston fixed to a diaphragm, it has heretofore been necessary, when cleaning the valve, to disassemble the pulsator by removing a cover arranged over the diaphragm, so that the diaphragm and the piston fixed to it can be removed and taken apart. This entails a risk of leakage between the diaphragm and the cover or between the diaphragm and the valve housing, or both, because when reassembling the parts, small particles may easily lodge between the tightening or sealing surfaces and cause a leakage.

The principal object of the present invention is to provide an improved pulsator of the type described in which the above-noted inconvenience is avoided.

A pulsator made according to the invention comprises a valve housing containing a sliding valve-piston, a diaphragm in the housing at one end of the piston, and a bayonet joint or catch by which the piston is secured to the diaphragm, the end of the housing remote from the diaphragm preferably having a detachable cover or bottom to permit removal of the piston from beneath the diaphragm.

For a better understanding of the invention, reference may be had to the accompanying drawing, in which Fig. 1 is a side elevational view, partly in section, of a preferred form of the new pulsator;

Fig. 2 is an enlarged vertical sectional view of part of the pulsator of Fig. 1, showing details of the connection between the diaphragm and the valve piston;

Fig. 3 is a bottom view of the washer permanently fixed to the diaphragm in Figs. 1 and 2, and

Figs, 4 and 5 are side elevational and plan views, respectively, of the upper part of the piston.

The pulsator housing I encloses a diaphragm 3 secured between a cover 4 of the housing and the housing proper. A bottom 5 detachably fixed to the pulsator housing closes the central cavity of the housing, which contains a piston B. The upper end portion of the piston 6 has an annular groove 1 above which is a flange 8. The flange has one or more cutofi portions 8a so as to give it a non-circular, preferably oblong shape, as seen from above. The flange fits into and can be introduced through an oblong opening 9 in a central depression of a Washer l0 fixed to the bottom of diaphragm 3. By turning the piston 90 3 Claims, (Cl. 137-403) relative to the washer t0, the longer ends of the flange 8 are made to engage with the edges of the opening 9, as shown in Fig. 2. The depression of the Washer 10 comprises a central cylindrical portion H enclosing the flange 8. An elastic or resilient pin l2 extends diametrically through the depression II and is loosely seated therein. After inserting the piston through the opening 9, the upper end of the piston contacts the pin l2. The end of the piston is provided with a diametrical groove M in which the pin [2 engages after the piston has been turned The piston is thus fixed in its angular position and cannot unintentionally be turned to a position in which it is released from the washer In. As shown by Fig. 4, however, the edges of the groove M are slanting, so that by applying sufficient force the piston can be turned until it disengages the groove I 4. It will be apparent that the flange 8 and the washer H) are in effect bayonet plug and socket members, respectively, which together form a bayonet catch releasably connecting the piston and its diaphragm 3.

When the piston 6 is to be removed, the bottom 5, which may be fixed to the pulsator housing by screws (not shown), is loosened. Then a special tool is introduced into the central bore of the piston B, and the latter is turned 90 with the tool and drawn out of the Washer l0 and the open ing in the end of the pulsator housing. When assembling the pulsator, the piston is introduced the same way into the central cavity of the pulsator housing, and the upper part of the piston is pushed through the opening 9 of the washer l 0 and turned. In this way, the piston 6 is fixed to the Washer l 6 and the diaphragm 3 in a manner which insures that it will not work loose during operation of the pulsator.

It will be understood that the piston 6, under control of diaphragm 3, acts as its own motor and reciprocates in the housing so as to establish alternating high and low pneumatic pressures for each teat cup, as disclosed, for example, in Hapgood Patent No. 2,379,483, dated July 3, 1945.

I claim:

1. In a pneumatic pulsator having a pulsator housing, a rotatable valve piston reciprocable in the housing, and a diaphragm in the housing located at one end of the piston for controlling the reciprocation thereof, the improvement which comprises bayonet plug and socket members, one secured to the piston and the other secured to the diaphragm, said members being interengageable by rotation of the piston to a locking position, with the plug member in the socket member,

to form a bayonet catch releasably connecting the piston and the diaphragm, the housing having an opening located near the end of the piston remote from the diaphragm and through which the piston is removable independently of the diaphragm upon rotating the piston from said locking position to disengage said bayonet catch, said plug member having a groove, and a resilient pin mounted in the socket member and located to be received by said groove in the locking position of the piston and thereby hold the piston against rotation from said position.

2. The improvement according to claim 1, in which the socket member is a Washer having an outer portion secured to the diaphragm and also having a cylindrical depression provided at the bottom with a non-circular opening for receiving said plug member, the resilient pin being located between the diaphragm and said opening.

3. In a pneumatic pulsator having a pulsator housing, a rotatable valve piston reciprocable in the housing, and a diaphragm in the housing located at one end of the piston for controlling the reciprocation thereof, the improvement which comprises a Washer having a fiat outer portion secured to the diaphragm and also having a central depression provided with a non-circular opening, and a non-circular flange on said end of the piston receivable in the opening and having a maximum diameter not exceeding the piston diameter, the piston being rotatable in the housing to a locking position in which the flange is located between the diaphragm and the washer at the edges of the opening, thereby connecting the piston and the diaphragm, and the housing having an opening near the end of the piston remote from the diaphragm and through which the piston and flange are removable independently of the diaphragm upon rotating the piston from said locking position.

SVEN JOHAN ERLING.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,051,965 Roth Aug. 25, 1936 2,379,483 Hapgood July 3, 1945 FOREIGN PATENTS Number Country Date 106,422 Great Britain May 24, 1917 

